Added a keymat_t version to cast it safely

src/libcharon/sa/ikev1/keymat_v1.c

@@ -946,6 +946,12 @@ METHOD(keymat_v1_t, confirm_iv, void,
 	}
 }
 
+METHOD(keymat_t, get_version, ike_version_t,
+	private_keymat_v1_t *this)
+{
+	return IKEV1;
+}
+
 METHOD(keymat_t, create_dh, diffie_hellman_t*,
 	private_keymat_v1_t *this, diffie_hellman_group_t group)
 {
@@ -984,6 +990,7 @@ keymat_v1_t *keymat_v1_create(bool initiator)
 	INIT(this,
 		.public = {
 			.keymat = {
+				.get_version = _get_version,
 				.create_dh = _create_dh,
 				.get_aead = _get_aead,
 				.destroy = _destroy,

src/libcharon/sa/ikev2/keymat_v2.c

@@ -71,6 +71,12 @@ struct private_keymat_v2_t {
 	chunk_t skp_verify;
 };
 
+METHOD(keymat_t, get_version, ike_version_t,
+	private_keymat_v2_t *this)
+{
+	return IKEV2;
+}
+
 METHOD(keymat_t, create_dh, diffie_hellman_t*,
 	private_keymat_v2_t *this, diffie_hellman_group_t group)
 {
@@ -563,6 +569,7 @@ keymat_v2_t *keymat_v2_create(bool initiator)
 	INIT(this,
 		.public = {
 			.keymat = {
+				.get_version = _get_version,
 				.create_dh = _create_dh,
 				.get_aead = _get_aead,
 				.destroy = _destroy,

src/libcharon/sa/keymat.h

@@ -36,6 +36,13 @@ typedef struct keymat_t keymat_t;
  */
 struct keymat_t {
 
+	/**
+	 * Get IKE version of this keymat.
+	 *
+	 * @return			IKEV1 for keymat_v1_t, IKEV2 for keymat_v2_t
+	 */
+	ike_version_t (*get_version)(keymat_t *this);
+
 	/**
 	 * Create a diffie hellman object for key agreement.
 	 *